Preparation device and preparation method of composite fire extinguishing microcapsule

Abstract

The invention provides a preparation device and a preparation method of a composite fire extinguishing microcapsule, and belongs to the technical field of fire extinguishing microcapsules, the preparation device comprises a first emulsion preparation assembly, a first curing assembly, a second emulsion preparation assembly and a second curing assembly; the first emulsion preparation assembly is used for preparing microcapsule emulsion containing an internal phase reagent, a light curing agent and a dispersing agent; the first curing assembly is used for carrying out light curing on the microcapsule emulsion to form a single-layer microcapsule; the second emulsion preparation assembly is used for mixing the sodium alginate aqueous solution and the single-layer microcapsules; the second curing component is used for providing a calcium ion solution to cure the sodium alginate to form a capsule coating layer. The purpose of preparing the composite fire extinguishing microcapsule with the double-layer capsule shell is achieved, the preparation efficiency and the consistency of product performance are greatly improved, and meanwhile the defect that an existing ultraviolet lamp is not uniform in microcapsule curing is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of fire - extinguishing microcapsules, and particularly to a preparation device and a preparation method for composite fire - extinguishing microcapsules. Background Art

[0002] At present, compared with traditional methods such as interfacial polymerization and in - situ polymerization, using microfluidic technology to prepare perfluorooctanone fire - extinguishing microcapsules is more time - saving and labor - saving. During the preparation process, heating is not required, which reduces the volatilization of the fire - extinguishing agent, enabling more perfluorooctanone fire - extinguishing agents to be encapsulated into the microcapsules. Moreover, the microcapsules prepared by microfluidic technology have a more uniform particle size and do not show a wide particle - size distribution.

[0003] Currently, patents for using microfluidics to prepare microcapsules usually use a single - layer photocurable resin to encapsulate perfluorooctanone. However, since perfluorooctanone is a volatile substance, it is difficult to achieve its long - term sealed storage with a single - layer encapsulation, resulting in a low encapsulation rate of the microcapsules. At the same time, existing photocuring processes mostly use simple bilateral light sources. This method not only easily leads to uneven curing of the microcapsules but also increases the cost to a certain extent. The above problems jointly affect the fire - extinguishing effect of the microcapsules, making it difficult for their performance to reach an ideal level.

[0004] During the preparation process of microcapsules, microfluidic technology faces some practical challenges. For example, the inner needle of the stainless - steel coaxial needle may experience problems such as channel rusting and blockage due to the long - term transportation of perfluorooctanone, affecting the normal operation of the equipment. In addition, the speed of generating microcapsule emulsion using a single coaxial needle in microfluidics is relatively slow, which significantly limits the production efficiency of microcapsules. At the same time, the syringe for injecting liquid into the microfluidic system needs to be frequently disassembled during use, increasing the operation complexity and further reducing the production efficiency of fire - extinguishing microcapsules. These problems have restricted the wide application and performance optimization of microcapsule technology to a certain extent. Therefore, it is of great significance to develop a preparation device and method with a high encapsulation rate, uniform curing effect, stable quality, and high production efficiency. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a preparation device and a preparation method for composite fire - extinguishing microcapsules, aiming to solve the technical problems of low capsule encapsulation rate, uneven curing, and insufficient quality stability in the existing preparation methods of fire - extinguishing microcapsules.

[0006] In a first aspect, the present invention provides a preparation device for composite fire - extinguishing microcapsules, including a first emulsion preparation component, a first curing component, a second emulsion preparation component, and a second curing component; The first emulsion preparation component is used to prepare a microcapsule emulsion containing an inner - phase reagent, a photo - curing agent, and a dispersant; The first curing component is arranged on the outlet side of the first emulsion preparation component and is used to perform photocuring on the microcapsule emulsion obtained by the first curing component to form monolayer microcapsules. The first curing component includes a multi-faceted mirror chamber, a collector, and an ultraviolet light curing lamp. The collector is arranged in the multi-faceted mirror chamber. There is a slit on the surface of the multi-faceted mirror chamber, and the ultraviolet light curing lamp light source is projected into the multi-faceted mirror chamber through the slit. One liquid inlet of the second emulsion preparation component is communicated with the liquid outlet of the collector of the first curing component. The second emulsion preparation component is used to mix the sodium alginate aqueous solution and the monolayer microcapsules. The second curing component is communicated with the liquid outlet of the second emulsion preparation component and is used to provide a calcium ion solution to solidify sodium alginate to form a capsule coating layer.

[0007] Preferably, the first emulsion preparation component includes an improved coaxial needle unit, an internal phase injection unit, a photocuring phase injection unit, a dispersion phase injection unit, and a microfluidic pressure chamber. The improved coaxial needle unit includes multiple groups of coaxially arranged inner needles and outer needles. The internal phase injection unit is hermetically communicated with the inner needle and is used to provide the internal phase reagent to the inner needle. The photocuring phase injection unit is hermetically communicated with the outer needle and is used to provide the photocuring agent to the outer needle. The dispersion phase injection unit is hermetically communicated with the microfluidic pressure chamber and is used to provide the dispersant to the microfluidic pressure chamber.

[0008] Preferably, the concentration of the polyvinyl alcohol aqueous solution is 0.5wt%-5wt%.

[0009] Preferably, an internal phase channel, a photocuring phase channel, and a dispersion phase channel are provided in the first emulsion preparation component. The end of the internal phase channel far from the inner needle is communicated with the internal phase injection unit, and the end of the internal phase channel close to the inner needle is communicated with the inner needle. The end of the photocuring phase channel far from the outer needle is communicated with the photocuring phase injection unit, and the end of the photocuring phase channel close to the outer needle is communicated with the outer needle. The end of the dispersion phase channel far from the coaxial needle unit is communicated with the dispersion phase injection unit, and the end of the dispersion phase channel close to the coaxial needle unit is communicated with the microfluidic pressure chamber.

[0010] Preferably, the inner needle is a capillary tube containing acid-resistant material. The acid-resistant material can be glass, platinum, gold, etc., which can be selected according to the actual situation.

[0011] Preferably, the internal phase reagent is perfluorhexanone fire extinguishing agent. The photocuring agent is an ultraviolet light curing resin containing a photoinitiator. The dispersant is a polyvinyl alcohol aqueous solution. Preferably, one end of the microfluidic pressure chamber close to the improved coaxial needle unit is fixedly connected to the improved coaxial needle unit, and there is a small hole at the end of the microfluidic pressure chamber far from the improved coaxial needle unit for outputting the microcapsule emulsion.

[0012] In an embodiment of the present invention, the material of the microfluidic pressure chamber is quartz glass, which is convenient for observing the emulsion formation process from the outside and has strong airtightness.

[0013] In an embodiment of the present invention, the multi-faceted mirror chamber is formed by surrounding a cylinder with ten mirrors. Then, a single light source is adjusted to enter the mirrors through a slit at an appropriate incident angle, so that ultraviolet light can be completely reflected for a full circle, thereby enabling the microcapsules to be cured in all directions and improving the encapsulation rate of the microcapsules.

[0014] Preferably, the collector is filled with an aqueous solution of polyvinyl alcohol (PVA) with a concentration of 5wt% - 20wt% for dispersing the microcapsule emulsion; the high-concentration PVA aqueous solution prevents the microcapsules from sticking to each other during the curing process.

[0015] Preferably, the second emulsion preparation component includes a PDMS outer phase injection unit and a PDMS microfluidic chip; the PDMS microfluidic chip is provided with a first liquid inlet, a second liquid inlet, and a liquid outlet; the first liquid inlet is communicated with the liquid outlet of the collector, the second liquid inlet is communicated with the liquid outlet of the PDMS outer phase injection unit, and the liquid outlet of the PDMS microfluidic chip is communicated with the second curing component.

[0016] In an embodiment of the present invention, the PDMS microfluidic chip is a T-shaped PDMS microfluidic chip, which is composed of a traditional glass sheet and a polydimethylsiloxane chip with microchannels engraved thereon; the T-shaped PDMS microfluidic chip is provided with a first liquid inlet, a second liquid inlet, and a liquid outlet; the first liquid inlet is connected to the liquid outlet of the collector and injects the single-layer microcapsules output by the first curing component; the second liquid inlet is connected to the liquid outlet of the PDMS outer phase injection unit and injects an aqueous solution of calcium alginate with a concentration of 1wt% - 5wt%.

[0017] Preferably, the second curing component includes a chamber container and a magnetic stirrer; the container is placed on the magnetic stirrer; the container is used to hold an aqueous solution of a calcium ion compound; the magnetic stirrer is used to promote the uniform curing of calcium ions and sodium alginate.

[0018] In an embodiment of the present invention, the calcium ion compound includes at least one of calcium chloride, calcium nitrate, and calcium sulfate; the concentration of the aqueous solution of the calcium ion compound is 1wt% - 10wt%.

[0019] Preferably, the inner-phase injection unit, the photo-curing phase injection unit, the dispersed-phase injection unit, and the PDMS outer-phase injection unit all include a syringe and a liquid storage tank; the syringe is provided with a valve-equipped liquid inlet pipe and a valve-equipped liquid outlet pipe in mutually perpendicular directions; the valve-equipped liquid inlet pipe communicates with the liquid storage tank and is used to suck reagents into the syringe; among them, the valve-equipped liquid outlet pipes in the inner-phase injection unit, the photo-curing phase injection unit, and the dispersed-phase injection unit are used to inject reagents into the first emulsion preparation assembly; the valve-equipped liquid outlet pipe in the PDMS outer-phase injection unit is used to inject reagents into the second emulsion preparation assembly.

[0020] In a second aspect, the present invention provides a method for preparing a composite fire-extinguishing microcapsule, which is implemented by using the above-mentioned preparation device for a composite fire-extinguishing microcapsule, and includes the following steps: Introduce the inner-phase reagent, the photo-curing agent, and the dispersant into the first emulsion preparation assembly to form a microcapsule emulsion by mixing. Transport the microcapsule emulsion to the first curing assembly and obtain monolayer microcapsules by ultraviolet light curing. Transport the monolayer microcapsules to the second emulsion preparation assembly and mix them with an aqueous sodium alginate solution to obtain a monolayer microcapsule emulsion wrapped with sodium alginate. Transport the monolayer microcapsule emulsion wrapped with sodium alginate to the second curing assembly, mix it with an aqueous solution containing a calcium ion compound, and cure it under stirring to form a capsule coating layer to obtain the composite fire-extinguishing microcapsule.

[0021] Preferably, the flow rate ratio of the inner-phase reagent, the photo-curing agent, and the dispersant in the first emulsion preparation assembly is 40~70:40~70:500~1400.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) For the preparation device of the composite fire-extinguishing microcapsule provided by the present invention, first, monolayer microcapsules are prepared by using a flow-focusing microfluidic control device, and on this basis, a T-shaped PDMS two-dimensional microfluidic control device is used for further processing to form a microcapsule coating layer, and the composite fire-extinguishing microcapsule is prepared. By organically combining these two devices, the preparation efficiency of the fire-extinguishing microcapsule and the consistency of product performance are greatly improved. Among them, the first curing assembly of the present invention uses a multi-faceted mirror chamber, which solves the drawback of uneven curing of microcapsules by using ultraviolet lamps on both sides in the traditional method and improves the encapsulation rate of microcapsules under the condition of only using one ultraviolet curing lamp.

[0023] (2) The present invention uses multiple improved coaxial needles made of acid-resistant materials and a microfluidic chamber prepared from all-quartz, which can not only eliminate the corrosion effect of the highly efficient and environmentally friendly perfluorhexanone fire extinguishing agent on the microchannels, but also greatly shorten the microcapsule preparation time. Moreover, the transparent and clear microfluidic chamber is conducive to observing the formation process of the first emulsion. The present invention also uses a syringe that can replace reagents without disassembly, which can make the microcapsule production process more intelligent. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the overall structure of the preparation device for the composite fire-extinguishing microcapsules in Example 1 of the present invention; Figure 2 It is a schematic diagram of the structure of the improved coaxial needle and the microfluidic pressure chamber in Example 1 of the present invention; Figure 3 It is a top view of the ten-sided mirror chamber in Example 1 of the present invention; Figure 4 It is a thermogravimetric analysis diagram of the composite fire-extinguishing microcapsules prepared in Example 1 of the present invention; Figure 5 It is a Fourier transform infrared spectroscopy diagram of the composite fire-extinguishing microcapsules prepared in Example 1 of the present invention; Figure 6 It is a scanning electron microscope image of the composite fire-extinguishing microcapsules prepared in Example 1 of the present invention; Figure 7 It is a scanning electron microscope image of the composite fire-extinguishing microcapsules prepared in Example 1 of the present invention; Figure 8 It is an optical microscope image of the composite fire-extinguishing microcapsules prepared by the present invention.

[0025] Description of the Reference Numerals: 1 - First emulsion preparation component, 11 - Improved coaxial needle unit, 111 - Inner needle, 112 - Outer needle, 12 - Inner phase injection unit, 121 - Syringe, 122 - Liquid storage tank, 13 - Photo-curing phase injection unit, 14 - Dispersed phase injection unit, 15 - Microfluidic pressure chamber, 151 - Small hole, 16 - Inner phase channel, 17 - Photo-curing phase channel, 18 - Dispersed phase channel, 2 - First curing component, 21 - Multi-sided mirror chamber, 22 - Collector, 23 - Ultraviolet light curing lamp, 24 - Slit, 3 - Second emulsion preparation component, 31 - PDMS outer phase injection unit, 32 - PDMS microfluidic chip, 321 - First liquid inlet, 322 - Second liquid inlet, 323 - Liquid outlet, 4 - Second curing component, 41 - Container, 42 - Stirrer. Detailed Embodiments

[0026] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] Embodiment 1 Please refer to Figure 1 、 Figure 2 and Figure 3 , this embodiment provides a preparation device for composite fire-extinguishing microcapsules, including: a first emulsion preparation component 1, a first curing component 2, a second emulsion preparation component 3, and a second curing component 4; The first emulsion preparation component 1 includes an improved coaxial needle unit 11, an internal phase injection unit 12, a photo-curing phase injection unit 13, a dispersed phase injection unit 14, and a microfluidic pressure chamber 15; an internal phase channel 16, a photo-curing phase channel 17, and a dispersed phase channel 18 are provided in the first emulsion preparation component 1; one end of the internal phase channel 16 far from the internal needle 111 is communicated with the internal phase injection unit 12, and one end of the internal phase channel 16 close to the internal needle 111 is communicated with the internal needle 111; one end of the photo-curing phase channel 17 far from the external needle 112 is communicated with the photo-curing phase injection unit 13, and one end of the photo-curing phase channel 17 close to the external needle 112 is communicated with the external needle 112; one end of the dispersed phase channel 18 far from the improved coaxial needle unit 11 is communicated with the dispersed phase injection unit 14, and one end of the dispersed phase channel 18 close to the improved coaxial needle unit 11 is communicated with the microfluidic pressure chamber 15.

[0028] The first microcapsule emulsion preparation component 1 is used for mixing different preparation reagents of the composite fire-extinguishing microcapsules to form a microcapsule emulsion; the internal phase reagent is transported by the internal phase injection unit 12 through the internal phase channel 16 to the internal needle 111 of the improved coaxial needle unit 11; the photo-curing agent is transported by the photo-curing phase injection unit 13 through the photo-curing phase channel 17 to the external needle 112 of the improved coaxial needle unit 11; the dispersant is transported by the dispersed phase injection unit 14 through the dispersed phase channel 18 to the microfluidic pressure chamber 15; the internal phase reagent, the photo-curing agent, and the dispersant are mixed in the microfluidic pressure chamber 15 to form a microcapsule emulsion.

[0029] The first curing component 2 is arranged on one side of the outlet of the first emulsion preparation component 1, and is used for photo-curing the microcapsule emulsion obtained by the first curing component 1 to form single-layer microcapsules; the first curing component includes a multi-faceted mirror chamber 21, a collector 22, and an ultraviolet photo-curing lamp 23; the collector 22 is arranged in the multi-faceted mirror chamber 21, a slit 24 is provided on the surface of the multi-faceted mirror chamber 21, and the light source of the ultraviolet photo-curing lamp 23 penetrates through the slit 24 and enters the multi-faceted mirror chamber 21.

[0030] The second emulsion preparation component 3 includes a PDMS outer phase injection unit 31 and a PDMS microfluidic chip 32; the PDMS microfluidic chip 32 is provided with a first liquid inlet 321, a second liquid inlet 322 and a liquid outlet 323; the first liquid inlet 321 is communicated with the liquid outlet of the collector 22, the second liquid inlet 322 is communicated with the liquid outlet of the PDMS outer phase injection unit 31, and the liquid outlet of the PDMS microfluidic chip 32 is communicated with the second curing component 4; the second emulsion preparation component 3 is used for mixing the sodium alginate aqueous solution and the monolayer microcapsules.

[0031] The second curing component 4 includes a chamber container 41 and a magnetic stirrer 42; the container 41 is used for containing an aqueous solution of a calcium ion compound; the magnetic stirrer 42 is used for promoting the uniform curing of calcium ions and sodium alginate. The second curing component 4 is communicated with the liquid outlet of the second emulsion preparation component 3, and is used for providing a calcium ion solution to cure sodium alginate to form a capsule coating layer.

[0032] Next, each component of the preparation device for the composite fire extinguishing microcapsules in the present invention will be described in detail.

[0033] The improved coaxial needle unit 11 includes 6 groups of coaxially arranged inner needles 111 and outer needles 112; the inner needle 111 is a capillary tube containing an acid-resistant material; 6 inner needles are axially fixedly connected using a circular thin sheet made of an acid-resistant material, and 6 stainless steel coaxial outer needles are axially fixedly connected using a stainless steel circular thin sheet. The improved coaxial needle unit 11 is placed above the microfluidic pressure chamber 15. The upper end of the chamber of the microfluidic pressure chamber 15 is penetrated with six groups of improved coaxial needles, and six liquid outlet small holes 151 are provided at the lower end, which are used for spraying the microcapsule emulsion into the first curing component 2.

[0034] The multi-faceted mirror chamber 21 is formed by surrounding a class cylinder with ten mirrors, and then adjusting the single light source of the ultraviolet curing lamp 23 to enter the inside of the mirror at a suitable incident angle (2° - 80°) through the slit 24, so that the ultraviolet light can be completely reflected back to the origin in a circle, and then reciprocated to achieve the effect of omnidirectional irradiation, thereby being able to cure the microcapsules omnidirectionally and improve the encapsulation rate of the microcapsules.

[0035] The collector 22 is a separating funnel, and the separating funnel is filled with an aqueous solution of polyvinyl alcohol (PVA) with a concentration of 5wt% - 20wt%, which is used for dispersing the microcapsule emulsion; the high-concentration PVA aqueous solution enables the microcapsules not to stick to each other during the curing process.

[0036] The PDMS microfluidic chip 32 is a T-shaped PDMS microfluidic chip, which is composed of a traditional glass sheet and a polydimethylsiloxane chip with microchannels engraved thereon; the T-shaped PDMS microfluidic chip is provided with a first liquid inlet 321, a second liquid inlet 322 and a liquid outlet 323; the first liquid inlet 321 is connected to the liquid outlet of the collector 22, and the single-layer microcapsules output by the first curing component 2 are injected; the second liquid inlet 322 is connected to the liquid outlet of the PDMS outer phase injection unit 31, and the aqueous calcium alginate solution is injected, and the concentration of the aqueous calcium alginate solution is 1wt%-5wt%.

[0037] The internal phase injection unit 12, the photocuring phase injection unit 13, the dispersed phase injection unit 14 and the PDMS outer phase injection unit 31 all include a syringe and a liquid storage tank; taking the internal phase injection unit 12 as an example, the internal phase injection unit 12 includes a syringe 121 and a liquid storage tank 122; the syringe 121 is provided with a liquid inlet pipe with a valve and a liquid outlet pipe with a valve in a mutually perpendicular direction; the liquid outlet pipe with a valve is used to inject reagents into the first emulsion preparation component 1; the liquid inlet pipe with a valve is communicated with the liquid storage tank 122 and is used to suck reagents into the syringe.

[0038] This embodiment also provides a preparation method of composite fire-extinguishing microcapsules, which includes the following steps: S1. Prepare the reagents required for the preparation of the first microcapsule emulsion, that is, prepare the corresponding reagents for the syringes of the internal phase injection unit 12, the photocuring phase injection unit 13, the dispersed phase injection unit 14 and the corresponding liquid storage tanks (the internal phase reagent is perfluorohexanone, the photocuring agent is ethoxylated trimethylolpropane triacrylate containing a photoinitiator, the photoinitiator is 2-hydroxy-2-methyl-1-phenylpropanone, and the dispersant is a 2wt% aqueous solution of polyvinyl alcohol), and then start the syringe. According to the preset propulsion flow rates (the flow rates of the internal phase reagent, the photocuring agent, and the dispersant are: 60 mL / h, 60 mL / h, and 1000 mL / h respectively), the liquid of each phase can flow into the improved coaxial needle unit 11 and the microfluidic pressure chamber 15 at the same time, and then the microcapsule emulsion will be ejected from the small hole 151 at the center of the lower part of the microfluidic pressure chamber 15, and thus drop into the first curing component 2 below; S2. After the microcapsule emulsion drops into the first curing component 2 and is cured by ultraviolet light irradiation, the microcapsules will sink to the bottom of the collector 22 (separatory funnel). After accumulating to a thickness of 2-3 cm, open the valve at the bottom, and the microcapsules will flow into the second emulsion preparation component 3 due to gravity. S3. When the microcapsules flow into the first liquid inlet 321 of the second emulsion preparation component 3, open the second liquid inlet 322 of the PDMS microfluidic chip 32. At this time, the PDMS outer phase injection unit 31 injects the sodium alginate aqueous solution into the channel of the PDMS microfluidic chip 32 at a flow rate matching the gravity sedimentation rate of the first layer of microcapsules, and an emulsion in which the sodium alginate aqueous solution wraps the single-layer microcapsules will be formed in the PDMS microfluidic chip 32. This emulsion flows into the container 41 of the second curing component 4 through the liquid outlet 323 of the PDMS microfluidic chip 32; S4. The container 41 of the second curing component 4 is filled with a 2wt% calcium chloride aqueous solution. The container 41 is placed on a magnetic stirrer 42, and a capsule coating layer will be formed by stirring to obtain the composite fire-extinguishing microcapsules.

[0039] See Figure 4 , thermogravimetric analysis was carried out on the composite fire-extinguishing microcapsules prepared by the device of the present invention. The heating range was set to be 30°C to 800°C, and the heating rate was 10°C / min to obtain a graph of the change in the weight percentage of the composite fire-extinguishing microcapsules with temperature. It can be seen that the mass encapsulation rate of the microcapsules is 89%, and the microcapsules can burst instantaneously at 249°C.

[0040] See Figure 5 , Figure 5 is the Fourier transform infrared spectrum of the composite fire-extinguishing microcapsules. This was measured by collecting the exhaust gas during the thermogravimetric process. By comparing with the Fourier transform infrared spectrum of pure perfluoromethylcyclohexanone, it can be seen that there is a unique C=O absorption peak of perfluoromethylcyclohexanone at a wavenumber of 1783 cm -1 in the gas released by the bursting of the composite fire-extinguishing microcapsules, which can prove that the perfluoromethylcyclohexanone is encapsulated in the composite fire-extinguishing microcapsules.

[0041] See Figure 6 and Figure 7 , Figure 6 , Figure 7 are the scanning electron microscope images of the composite fire-extinguishing microcapsules. It can be clearly seen that a calcium alginate layer is wrapped outside the photocurable resin microcapsules, and the microcapsules are relatively smooth as a whole. The particle size of the composite fire-extinguishing microcapsules is between 300 μm and 400 μm, and the thickness of the calcium alginate layer is between 20 μm and 30 μm. Therefore, the capsule shell of the composite fire-extinguishing microcapsules is relatively thin, thus achieving a high encapsulation of the perfluoromethylcyclohexanone fire extinguishing agent by the microcapsules.

[0042] See Figure 8 , Figure 8 is the optical microscope image of the composite fire-extinguishing microcapsules. It can be clearly seen that the surface of the microcapsules is relatively smooth and the shape is close to spherical.

[0043] It should be noted that the present invention is not limited to the above embodiments. The above embodiments are only examples, and embodiments having the same composition in essence as the technical idea and achieving the same effect within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, within the scope of not departing from the gist of the present invention, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways constructed by combining some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A preparation device for composite fire extinguishing microcapsules, characterized in that: It includes a first emulsion preparation component, a first curing component, a second emulsion preparation component and a second curing component; The first emulsion preparation component is used to prepare a microcapsule emulsion containing an internal phase reagent, a photocuring agent and a dispersant; The first curing component comprises a multi-faceted reflector chamber, a collector and an ultraviolet curing lamp; the collector is arranged in the multi-faceted reflector chamber, a slit is arranged on the surface of the multi-faceted reflector chamber, and the light source of the ultraviolet curing lamp is emitted into the multi-faceted reflector chamber through the slit; the first curing component is arranged at the outlet side of the first emulsion preparation component, and is used to photo-curing the microcapsule emulsion obtained by the first curing component to form a single-layer microcapsule; A liquid inlet of the second emulsion preparation component is connected to a liquid outlet of the collector of the first curing component, and the second emulsion preparation component is used to mix the sodium alginate aqueous solution with the single-layer microcapsules; The second solidification component is communicated with the liquid outlet of the second emulsion preparation component, and is used to provide a calcium ion solution to solidify the sodium alginate to form a capsule coating layer.

2. The preparation device of a composite fire extinguishing microcapsule according to claim 1, characterized in that: The first emulsion preparation assembly includes a modified coaxial needle unit, an internal phase injection unit, a photocurable phase injection unit, a dispersed phase injection unit, and a microfluidic pressure chamber; The improved coaxial needle unit comprises a plurality of groups of coaxially arranged inner needles and outer needles; The inner phase injection unit is sealed and connected to the inner needle for providing the inner phase reagent to the inner needle; the photocuring phase injection unit is sealed and connected to the outer needle for providing the photocuring agent to the outer needle; the dispersed phase injection unit is sealed and connected to the microfluidic pressure chamber for providing the dispersed agent to the microfluidic pressure chamber.

3. The preparation device of a composite fire extinguishing microcapsule according to claim 2, characterized in that: The inner needle is a capillary containing an acid-resistant material; the inner phase reagent is a perfluorohexanone fire extinguishing agent; the photocuring agent is an ultraviolet light-curing resin containing a photoinitiator; and the dispersant is a polyvinyl alcohol aqueous solution.

4. The preparation device of a composite fire extinguishing microcapsule according to claim 2, characterized in that: The end of the microfluidic pressure chamber close to the improved coaxial needle unit is fixedly connected to the improved coaxial needle unit; the end of the microfluidic pressure chamber away from the improved coaxial needle unit is provided with a small hole for outputting microcapsule emulsion.

5. The preparation device of a composite fire extinguishing microcapsule according to claim 1, characterized in that: The collector is filled with a polyvinyl alcohol aqueous solution with a concentration of 5wt%-20wt% for dispersing the microcapsule emulsion.

6. The preparation device of a composite fire extinguishing microcapsule according to claim 2, characterized in that: The second emulsion preparation component includes a PDMS external phase injection unit and a PDMS microfluidic chip; the PDMS microfluidic chip is provided with a first liquid inlet, a second liquid inlet and a liquid outlet; the first liquid inlet is connected to the liquid outlet of the collector, the second liquid inlet is connected to the liquid outlet of the PDMS external phase injection unit, and the liquid outlet of the PDMS microfluidic chip is connected to the second curing component.

7. The preparation device of a composite fire-extinguishing microcapsule according to claim 1, characterized in that: The second solidification component comprises a chamber container and a magnetic stirrer; the container is placed on the magnetic stirrer; the container is used to contain an aqueous solution containing a calcium ion compound; and the magnetic stirrer is used to promote uniform solidification of calcium ions and sodium alginate.

8. The preparation device of the composite fire extinguishing microcapsule according to claim 6, characterized in that: The inner phase injection unit, the photocurable phase injection unit, the dispersed phase injection unit, and the PDMS outer phase injection unit all include a syringe and a liquid storage tank; the syringe is provided with a liquid inlet pipe with a valve and a liquid outlet pipe with a valve in mutually perpendicular directions; the liquid inlet pipe with a valve is connected to the liquid storage tank and is used to suck the reagent into the syringe; Among them, the liquid outlet pipe with valve in the internal phase injection unit, the photocuring phase injection unit and the dispersed phase injection unit is used to inject reagents into the first emulsion preparation component; the liquid outlet pipe with valve in the PDMS external phase injection unit is used to inject reagents into the second emulsion preparation component.

9. A method for preparing a composite fire-extinguishing microcapsule, implemented by using the composite fire-extinguishing microcapsule preparation device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Passing an internal phase reagent, a light curing agent and a dispersant into the first emulsion preparation component and mixing them to form a microcapsule emulsion; The microcapsule emulsion is transported to the first curing component to obtain a single-layer microcapsule by ultraviolet curing; The single-layer microcapsules are transported to the second emulsion preparation component and mixed with the sodium alginate aqueous solution to obtain a single-layer microcapsule emulsion wrapped with sodium alginate; The sodium alginate-wrapped single-layer microcapsule emulsion is transported to the second curing component, mixed with an aqueous solution containing a calcium ion compound, and cured under stirring to form a capsule coating layer to obtain a composite fire-extinguishing microcapsule.

10. The method for preparing a composite fire-extinguishing microcapsule according to claim 9, characterized in that: The flow ratio of the internal phase reagent, the light curing agent and the dispersant is 40-70:40-70:500-1400.

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